Line-force-driven wind from a thin disk in a tidal disruption event

¹ Shanghai Key Lab for Astrophysics, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
² Department of Physics and Chongqing Key Laboratory for Strongly Coupled Physics, Chongqing University, Chongqing 400044, PR China
³ Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030, China
⁴ Polar Research Institute of China, 451, Jinqiao Road, Pudong, Shanghai 200136, China
⁵ Department of Physics, Nanjing Normal University, Nanjing 210023, China

^★ Corresponding authors: This email address is being protected from spambots. You need JavaScript enabled to view it. ; This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 29 June 2025
Accepted: 19 October 2025

Abstract

Context. Winds from the accretion disk in tidal disruption events (TDEs) play a key role in determining their observed emission. While winds from the super-Eddington accretion phase in TDEs have recently been studied, the properties of winds from the sub-Eddington accretion disk remain unclear.

Aims. We aimed to investigate the properties of winds from the circularized sub-Eddington accretion disk in TDEs and study the line-force-driven accretion disk wind.

Methods. We performed two-dimensional hydrodynamic simulations using the PLUTO code to study the line-force-driven wind from the circularized accretion disk around a 10⁶ solar mass black hole in TDEs.

Results. We find that although the disk is very small in TDEs, a strong wind can be driven by line force when the disk has a luminosity greater than 20% of the Eddington luminosity. The maximum velocity of the wind can reach up to 0.3 times the speed of light. The kinematic power of wind ranges from 1 − 6% of the Eddington luminosity.

Conclusions. Strong winds can be driven by line force from the thin disk around a 10⁶ solar mass black hole in TDEs. We briefly discuss the possible radio emission from the shock when the wind collides with the surrounding medium.